The present invention relates to a vehicular headlight, particularly to a aiming apparatus to be incorporated for adjusting orientation of a reflector of the headlight so as to optimize the direction of illumination when the headlight is attached to a vehicular body and also to a process for manufacturing a headlight using the same.
An exemplary constitution of a aiming apparatus 80 in a prior headlight 90 is shown in FIGS. 7 and 8. A reflector 91 is provided with a ball joint 81 at a lower right corner thereof with respect to the direction of fitting the reflector to a housing 92 and also with adjusting nuts 82 at an upper right corner directly above the ball joint and at a lower left corner (not shown) in alignment horizontally with the ball joint, respectively, in the state where the reflector 91 is attached to the housing 92.
Meanwhile, the housing 92 is provided with a ball receiver 81a at a lower right corner thereof to oppose the ball joint 81 and also with a pair of adjusting screws 82a to oppose the adjusting nuts 82 respectively. One adjusting screw 82a located at the upper right cornet is for adjusting vertically the orientation of the reflector; whereas the other adjusting screw 82a (not shown) located at the lower left corner is for adjusting horizontally the orientation of the reflector.
The headlight 90 having the constitution as described above is assembled by fitting first the ball joint 81 in the ball joint receiver 81a and then threading the adjusting screws 82a into the opposing adjusting nuts 82 respectively to achieve fitting of the reflector 91 to the housing 92, followed finally by fitting of a lens 93 to the housing 92.
It should be noted here that in FIG. 8, which is directed to minute illustration of the relationship between the adjusting nuts 82 and the adjusting screws 82a, the adjusting nuts 82 are fixed to substantially C-shaped nut holders 82b formed on the rear side of the reflector 91, respectively; whereas the adjusting screws 82a are each rotatably engaged at around the proximal end with the housing 92. If each adjusting screw 82a is, turned from the rear side of the housing, the opposing adjusting nut 82 is caused to move forward or backward along the adjusting screw 82a to enable changing of the orientation of the reflector 91 vertically or horizontally on the ball joint 81 serving as a pivot.
However, the prior aiming apparatus 80 involves a problem that the procedures of fitting the reflector 91 to the housing 92 is difficult, intricate and time-consuming, since engagement of the adjusting screws 82a with the adjusting nuts 82 are achieved respectively within the housing 92 under the condition where it is difficult to visually confirm them, and each adjusting screw 82 must be driven into the opposing adjusting nut 82 until the nut reaches an appropriate position of the opposing adjusting screw 82a. 
There is another problem that the number of steps is increased. The reason is that it is difficult to align each adjusting screw 82a with the opposing adjusting nut 82 between them since the alignment is achieved respectively within the housing 92. As a result, there occurs a wide variation in the orientation of the reflectors 91 with respect to the housings respectively, and this inevitably requires readjustment of the reflectors 91 with respect to the direction of illumination, after the headlight 90 is assembled completely.
The present invention provides means, which can solve the problems inherent in the prior aiming apparatus. More specifically, the present invention provides a aiming apparatus to be interposed between a reflector and a housing to adjust direction of light reflected by the reflector; the aiming apparatus comprising an adjusting screw rotatably engaged at one end (proximal end) with the housing at a predetermined position; a pivot nut having at one end (proximal end) a nut portion capable of achieving thread engagement with the other end (distal end) of. the adjusting screw and at the other end (distal end) a pivot portion, respectively; a pivot holder attached to a rear side of the reflector; said pivot holder being capable of pivotally holding the pivot portion; and a nut receiver fixed on the front side of the housing at a predetermined position; said nut receiver being capable of receiving slidably a guard-like sliding guide formed at a top of the pivot nut; wherein a longitudinal axial line of the nut receiver is parallel to an axial line X of the adjusting screw engaged with the nut portion; and the pivot nut has a height equal to the vertical distance between a position where the nut receiver is engaged with the housing and a position where one end (proximal end) of the adjusting screw is engaged with the housing.
It should be noted here that the expression xe2x80x9ca height equal to the vertical distance . . . xe2x80x9d means that, one end (proximal end) of the adjusting screw engaged with the nut portion is located at a predetermined engaging position of the housing, in the state where the sliding guides are received in the nut receiver such that the longitudinal axial line of the nut receiver and the axial line of the adjusting screw engaged with the nut portion are parallel to each other.